A modified procedure for the determination of 5-hydroxyindoleacetic acid in the urine and cerebrospinal fluid of patients with hepatic cirrhosis.

A method has been developed for the separation of 5-hydroxyindoleacetic acid from substances in urine and cerebrospinal fluid which interfere with its fluorometric determination. This involves the use of anion exchange column chromatography with elution of the 5-hydroxyindoleacetic acid by 3 mol/l formic acid in 60% methanol. The indole acid is then assayed fluorometrically after reaction with o-phtalaldehyde. Urinary 5-hydroxyindoleacetic acid values are reported for patients with stable cirrhosis and hepatic encephalopathy and compared with those found in control subjects without liver disease.